When WebKit is launched, it looks just like Safari. However, its icon is different (gold rimmed compass rather than silver) so you will be able to tell that you are running the WebKit version rather than Safari by looking in your Dock. Note that if you launch Safari as well, it will look like you have two Safaris running at once.

Thank you Jonathan. I had been thinking that OmniGroup was recommending that we install a newer version of WebKit which the OmniWeb sneaky peak would use. But I guess that's not the case?

I assumed that when OmniGroup says:

"OmniWeb is using a modified version of WebKit based off of revision 13295. You can download a nightly build of WebKit.app based on a similar version of WebKit from WebKit Nightlies. There isn't a WebKit Nightly directly corresponding with this revision however. We recommend testing against Revision 13302."

So, what we are really doing is having the ability to compare how the WebKit application renders a page to how OmniWeb renders a page?

And, downloading a nightly build of WebKit will not affect how the OmniWeb application functions because it uses its own "built-in" WebKit code?